Iron County register. [volume] (Ironton, Iron County, Mo.) 1867-1965, 1887-06-02
WOOD PRESERVATION.
The Method Successfully Adopted at the
Charlestown Navy Yard.

The Method Successfully Adopted at the
Charlestown Navy Yard. /
For many years there were many |
complaints and dissatisfaction with |
modern ships in the navy, because of |
their early decay, resulting from a law |
of nature which has never been entire |
" overcome. Many unsuccessful efforts |
have been made to do this, but thus
far practical tests have not demon
strated the thorough efficiency of any
of them. The process of preservation,
as applied at the Charlestown Navy
Yard, adopted in 1877, gives the most
the durability of the wood. The creo-
sote process was applied to several
ships, and, although meeting all re-
quirements as a preservative, it emit
ted strong odor which tainted all the
food on board ship, rendering it so dis
tasteful that it could not be eaten. For
this reason It was found necessary to
abandon this process. The chemicals
used in the present method of
preserving do not smell bad, and after
exposure to air or water for a few
admitted that this process is superior
to all others, and as it may be of inter-
est to many of the readers, here append
ed is given the method of timber pres
ervation by impregnation at the
Charlestown Navy Yard.
Timber OF all dimensions is loaded
on cars. which are run into copper
cylinder six feet in diameter and eighty
feet in length. A pipe leads from the
bottom of the copper boiler to steam
boiler; this pipe is pierced with numer-
Gus small holes to permit the free es-
cape of the steam. Steam is then adj
mitted, which will thoroughly saturate
the timber, pressing out the sap, with
the exception of some of its albumen
parts, which, together with the con-
densed water, will run off at the bot
tom of the copper cylinder. The
steam answers the double purpose of
driving out the sap, and at
the same time rendering the tim
Der. which as found in the mar
ket can not be expected always to be
evenly seasoned, uniformly prepared to
receive the impregnation. The gate at
the end of the boiler being hermetic-
ally sealed makes the huge cylinder
perfectly air tight. Now a powerful
air pump, connected with the cylinder,
is set in operation, for the double pur-
pose of extracting the condensed steam
contained in the timber and of extract
ing the air to form vacuum. When
the vacuum is established, the copper
cylinder is filled with solution of sui
phate of copper, and by means of a
force pump pressure OF from one
hundred to one hundred and twenty
pounds to the square inch is applied.
After the timber is saturated with sui
phate of copper the residuum is let off
and a vacuum is formed again, and a
solution of chloride of barium is adj
mitted. This forms, in short time a
chemical combination with the sulphate
of copper, forming insoluble salt
of sulphate of barytes, and the timber
is ready for use.
The destruction of all wooden struct-
ures in saltwater by the ship worm is
only question of time when the wood
has not been impregnated. When the
temperature of the ocean is high this
ship worm will destroy wooden struct-
ures so thoroughly in two years that
they become thereby unfit and unsafe
for use and have to be renewed. AL
efforts to stop the action of these mi
crobes failed until this process was in
troduced. Many failed partly because
the nature of some application wa:
either such that they would not enter
into the green, sappy wood, or tina
they washed out easily by the action o
the water, and partly because such APP
plications were confined to an outside
coating, which, when removed from
any one given point, afforded no pro
lection, for worm after worm then en-
tered and the whole stick was quickly
destroyed. Even to case whole pile
with sheet copper is only temporary
though costly remedy, for only SO Ions
as the whole armor remains intact ant
incloses the stick in water-tight man
ner is it protected.
The nature of the process here de-
scribed is such that sticks of an,
length, even when cut the same day
can easily be impregnated thoroughly
from one end to the other, and tn
crystals precipitated along the inside
of the pores of the wood, as the resul
of the combination of the two chemie
ais, form coating inside thes
pores, which neither can be removed
by mechanical action nor the action O
water as sulphate of barytes is insolu
bile in water or acids. Soft wood, sucf
as pine, whitewood. beech. etc.
which, when unprepared, only las
TO
found when prepared by this process
to be in good and sound condition aft
er sixteen years service. Railroad
ties which have been impregnauet
have been found free from decay afte
exposure for fifteen years, which test
fies to the efficiency of impregnatior
Boston Manufacturers Gazette.